1. Field of the Invention
This invention relates generally to improved ester compositions, and more particularly to novel benzoate esters of hydroxyl terminated polyether polysiloxane copolyols, their process of manufacture and their use as a cosmetic ingredient for toiletry and cosmetic formulations. The esters are useful for personal care cleansing products, such as skin and hair care products, and bar and liquid soaps.
2. Description of the Related Art
Esters and acids are known for a variety of different applications for cosmetic, pharmaceutical and medicinal purposes. Benzoate esters of certain alcohols and alcohol mixtures, and their uses are disclosed in assignee""s U.S. Pat. Nos. 4,275,222, 4,322,545, 4,323,693, and 4,323,694 all to Scala, Jr.; U.S. Pat. Nos. 4,278,655, and 4,293,544 both to Elmi; and U.S. Pat. Nos. 5,271,930, 5270,421, and 4,791,097 all to Walele et al. The disclosures of these patents are incorporated herein by reference.
U.S. Pat. Nos. 5,807,545; 5,843,418, and 5,855,878 to Coffindaffer et al. disclose a vehicle system having a thickening system which comprises a nonionic long-chain alkylated water-soluble polymer and a specific cationic quaternary ammonium surfactant component dispersed in a compatible solvent. The vehicle system is used to deliver an active component to the hair or skin. Compositions containing said vehicle system may additionally contain a hair setting agent, a distributing aid, and a surfactant. Polysiloxanes and other silicone compounds are useful as hair conditioning components in the compositions of the invention.
U.S. Pat. No. 6,030,630 to Fleury et al. discloses a cosmetic composition for the hair and/or skin comprising at least one water-dispersible sulfonated copolyester containing polyorganosiloxane units incorporating a plurality of repeating sulfonated polyester units and polyorganosiloxane units.
U.S. Pat. No. 5,136,063 to O""Lenick, Jr. discloses silicone fatty esters prepared by esterification of a fatty carboxylic acid, ester or anhydride and a hydroxy containing silicone compound. Examples of suitable reactants are fatty acids such as lauric, myristic, stearic, oleic, and linoleic acid. These are esters of fatty acids, i.e., aliphatic long chain fatty carboxylic acids.
U.S. Pat. No. 5,166,297 to O""Lenick, Jr. discloses a dimethicone copolyol halo ester intermediate which is useful for reaction with amines to prepare silicone based quaternary compounds.
U.S. Pat. No.5,226,923 to O""Lenick, Jr. discloses processes for treating fiber with silicone fatty esters which act as conditioning agents for hair, skin, textile and other fibers. The silicone fatty esters are prepared by reacting the hydroxyl group in a silicone polymer with a fatty carboxylic acid, ester or anhydride, preferably in the presence of a catalyst. Examples of suitable reactants are fatty acids such as lauric, myristic, stearic, oleic, linoleic, and hydroxystearic.
U.S. Pat. No. 5292,847 To O""Lenick, Jr. discloses a series of silicone alkoxylates prepared by reacting a carboxy functional silicone and an ethylene oxide, propylene oxide or mixtures thereof. The products provide surfactant properties, specifically emulsification properties for many oil phases.
U.S. Pat. No. 5,296,625 to O""Lenick, Jr. et al. discloses a series of silicone alkoxylated esters which contain terminal carboxyl groups. The compounds are prepared by reacting the hydroxyl group in a silicone polymer with an anhydride. The compounds provide softening and lubrication when applied to fibers.
U.S. Pat. No. 5,378,787 to Vrckovnik et al. discloses a series of silicone reactive amino containing dimethicone copolyols. The amino silicone polymers are made by reacting an amino trialkoxy silane and a silanol to make an intermediate which is subsequently reacted with a dimethicone copolyol in the presence of alkaline catalyst. The reactive group is selected from silanol hydroxyl and optionally an alkoxy group.
U.S. Pat. No. 5,656,664 to O""Lenick, Jr. discloses esters prepared by reacting an alpha methyl alcohol and a fatty acid. A preferred ester is prepared using guerbet alcohols. The esters are useful as conditioning agents for skin.
U.S. Pat. Nos. 5,008,103 and 5,066,756 to Raleigh et al. disclose polysiloxane polymers containing organic polyether groups which are polysiloxane surface active agents for use in sun screen oils, antiperspirants, and the like.
U.S. Pat. No. 5,401,870 and 5,451,692 to Raleigh et al. disclose polysiloxane copolymers which are long chain hydrocarbon-modified polydiorganosiloxane polyoxyalkylene copolymers containing polydimethylsiloxy groups. The compounds are useful as emulsifiers in improved stability water-in-oil emulsions.
U.S. Pat. Nos. 5,658,558 and 5,939,058 to Schwartz disclose hair styling compositions containing at least one acrylic hair fixative resin and one or more plasticizing compounds selected from polycarboxylic acid esters and dimethicone copolyols.
U.S. Pat. No. 5,705,147 to Shapiro et al. discloses hair conditioning compositions comprising a mixture prepared by transesterification of a triglyceride with sucrose, and further comprising surfactants and optional ingredients such as polyether siloxane copolymers.
U.S. Pat. No. 5,710,113 to Wells discloses hair conditioning compositions containing a silicone fluid hair conditioning composition and silicone resin.
U.S. Pat. No. 6,022,547 to Herb et al. discloses a water-in-oil-in-water compositions including silicone-based surfactants comprising a dimethicone copolyol.
U.S. Pat. No. 4,654,161 to Kollmeier et al. discloses oxganopolysiloxanes that have one or more betaine groups, processes for their synthesis, and their use in cosmetic preparations.
U.S. Pat. No. 4,717,498 to Maxon et al. discloses dimethicone copolyol sulfosuccinate compounds obtained by reacting the ethoxylated polyether side chains of dimethicone copolyol with maleic anhydride to form a monester and then converting the monester to a sulfosuccinate by sulfonation of the double bond with a metallic sulfite, an amine or with a combination of a metallic sulfite and an amine. The compounds are useful as surfactants for improving the mildness and foam enhancing and stabilizing properties of shampoos and other personal care products.
U.S. Pat. No. 4,960,845 to O""Lenick, Jr. discloses sulfated silicone polymers which have the sulfate group on a pendant functionality rather than within the polymer backbone. The compounds provide a high level of foam in aqueous solution.
U.S. Pat. No. 5,070,168 to O""Lenick, Jr. discloses amino functional silicone polymers which have an ether amino pendant group. The compounds are prepared by introduction of an amino group on to the silicone pendant group. The compounds provide softness and lubrication to substrates.
U.S. Pat. No. 5,070,171 to O""Lenick, Jr. discloses organofunctional silicone polymers which have a phosphate pendant functionality present within the polymer. The phosphated silicone polymers are prepared by phosphation of a hydroxyl group on the silicone polymer.
U.S. Pat. No. 5,073,619 to O""Lenick, Jr. discloses organofunctional silicone polymers which have an amphoteric pendant functionality. The silicone amphoteric polymers are prepared by introduction of an amphoteric group by reaction of acrylic acid or methyl acrylate with a primary alkoxylated amine containing the silicone polymer. The compounds are good detergents and foaming agents.
U.S. Pat. No. 5,098,979 to O""Lenick, Jr. discloses quaternary silicone polymers useful in softening hair and fiber, and in conditioning skin. The compounds are silicone polymers which contain a quaternary nitrogen pendant group.
U.S. Pat. No. 5,120,812 to O""Lenick, Jr. discloses a vinyl silicone monomer which contains urethane functional groups, prepared by reaction of hydroxy containing silicone compounds with Benzene-1-(1-isocyanato-1-methylethyl)-3-(1-methylethenyl). The materials are used as intermediates in the preparation of polymers.
U.S. Pat. No.5,149,765 to O""Lenick, Jr. discloses a silicone phosphate compound prepared by the phosphation reaction of a terminal hydroxy group of a silicone polymer with a phosphating agent selected from the group consisting of polyphosphoric acid and phosphorus pentoxide. The compounds useful as raw materials are terminal dimethicone copolyols. The compounds of the invention provide a lubricant antistat which can be applied to a variety of fibers.
U.S. Pat. No. 5,153,294 to O""Lenick, Jr. discloses a series of ester containing quaternary silicone polymers prepared by the esterification reaction of chloroacetic acid with a pendant hydroxyl group which is present on a silicone polymer. Preferably, the hydroxy containing silicone polymer has been alkoxylated with ethylene oxide, propylene oxide, or mixtures thereof. The compounds are useful in softening hair, and fiber and conditioning skin.
U.S. Pat. No. 5,196,499 to O""Lenick, Jr. discloses a series of silicone ester quaternary polymers. The compounds are prepared by the esterification of a terminal hydroxy group which is present on a silicone polymer with monochloracetic acid, and subsequently reacting the chloro ester so produced with a tertiary amine to produce the desired quaternary compound. The compounds are substantive to fiber and provide softening properties to fibers, hair and skin.
U.S. Pat. No. 5,237,035 to O""Lenick, Jr. discloses silicone phospholipid polymers which are lubricants, have high levels of foam, and low irritation properties. The compounds are prepared by phosphation of terminal dimethicone copolyols, followed by reaction with epichlorohydrin followed by reaction with amines.
U.S. Pat. No. 5,248,783 to O""Lenick discloses silicone alkoxylated ester salts which contain terminal carboxyl groups which have been neutralized with various fatty amine compounds. The compounds are prepared by reacting the hydroxyl group in a silicone polymer with an anhydride, followed by neutralization with an amine. The compounds provide high dense foam and solubility in many organic solvents.
U.S. Pat. No. 5,280,099 to Imperante et al. discloses taurinie functional silicone polymers, useful in softening hair and fiber and conditioning skin. The compounds are prepared by reacting chloro silicone intermediate with a taurine derivative. In a preferred embodiment, the hydroxy containing silicone polymer has been alkoxylated with ethylene oxide, propylene oxide or mixtures thereof.
U.S. Pat. No. 5,300,666 to Imperante et al. discloses silicone isethionate polymers useful as detergents and softeners. The compounds are prepared by the reaction of a carboxy silicone with an isethionate to produce surface active materials useful in personal care applications such as soap bars.
However, none of these references teach or suggest the specific novel benzoate esters of hydroxyl terminated polyether polysiloxane copolyols of this invention or the use of such ester compositions as emollients, moisturizers, sunscreen vehicles/solvents, hair conditioners and detanglers, wetting agents for powders, de-oilers/degreasers, emulsifiers/co-emulsifiers, viscosity-modifiers, foam-modifiers, facial cleansers, etc.
It is an object of this invention to provide novel benzoate esters of hydroxyl terminated polyether polysiloxane copolyols having unique properties which make them uniquely suitable for use in cosmetics, skin care products, personal care products such as body washes, cleansers, creams, lotions, shampoos, and other topical applications and products.
Another object of the invention is to produce benzoate esters of hydroxyl terminated polyether polysiloxane copolyols which are useful for treating textiles and fibers.
It is a further object of this invention to provide benzoate esters of hydroxyl terminated polyether polysiloxane copolyols having superior properties, namely superior foam characteristics and skin feel as compared to other benzoate esters,
These and other objects are obtained by reacting benzoic acid with a hydroxyl terminated polyether polysiloxane copolyol. The compositions provided include many unique effects as compared to commercially available benzoate ester products.
The novel benzoate esters of this invention have unique properties in that they are substantially non-greasy, lack oiliness and greasiness, have low pour points, have a bland odor, low toxicity and are stable. These properties make the compositions useful as a vehicle or carrier, emollient or solubilizer for toiletry and cosmetic formulations such as hair creams, hand cleaners, bath oils, suntan oils, anti-perspirants, perfumes, colognes, cold creams, electric pre-shaves, eye and throat oils, finger nail polish, topical pharmaceutical ointments, lipsticks, stick rouge, skin lotions and creams, skin moisturizers, cleansing creams, and after bath splash and lotions, as well as other formulations.
A particularly useful composition of this invention, particularly for use in anti-perspirant compositions, sun screening compositions, perfumes, hair creams, hand cleaners, bath oils, suntan oils, 2 in 1 clear conditioning shampoos, clear conditioning shampoos, clear and mild skin cleansing gels, pearlescent hand soaps, bar soaps, creams and lotions for skin care, and the like, consists of a benzoate ester of hydroxyl terminated polyether polysiloxane co-polyols.
The hydroxyl terminated polyether polysiloxane co-polyols useful in making the benzoate esters of this invention may be represented by the following formula: 
In the above formula, x and y are each individually a number of one or greater, and preferably, each individually may be a number from 1 to 50.
R1, R2, R3 and R4 may all be the same or different, provided that at least one of R1, R2, R3 or R4 is a hydroxyl terminated polyether group, and preferably a hydroxyl terminated co-polyether group wherein one polyether group comprises ethylene oxide groups and the other polyether group comprises propylene oxide groups and mixtures thereof. Generally, the alkoxy groups of the polyether will be an ethylene oxide or propylene oxide.
The hydroxyl terminated polyether groups may be represented by the following structure:
(R5)pxe2x80x94O(R6xe2x80x94O)mxe2x80x94(R7xe2x80x94O)nxe2x80x94Hxe2x80x83xe2x80x83Formula II
wherein R5 may be an alkyl group of one to ten carbon atoms; p is a number from one to ten; R6 is an alkyl group of from two to twelve carbon atoms; m is a number from one to twenty; R7 is an alkyl group of from two to twenty carbon atoms; and n is a number from one to twenty.
When one of R1, R2, R3 and R4 is a hydroxyl terminated polyether as set forth above, the others may be selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, alkoxy, substituted alkyl, substituted aryl, and mixtures thereof.
It is preferred that R1, R1, R3 and R4 be methyl or di-methyl provided that at least one of R1, R2, R3 and R4 is a hydroxyl terminated polyether copolyol radical. In a preferred embodiment, the polyether polysiloxane copolyol will conform to the following formula, wherein R1, R2, and R3 are methyl groups: 
wherein s, t, u and v are each independently an integer of 1 or greater or the polyether polysiloxane copolyol may have the structure: 
wherein w and z are each independently an integer ranging from about 1 to 20 and g and h are each independently an integer ranging from about 1 to 50.
The hydroxyl terminated polyether polysiloxane copolyols useful in making the benzoate esters of this invention have the CTFA name of dimethicone copolyol and are also known as silicone glycol copolymer or polysiloxane polyether copolymers.
The hydroxyl terminated polyether polysiloxane copolyols useful in making the benzoate esters of this invention may be obtained from Union Carbide Chemicals and Plastics Company Inc. of Danbury, Conn. 06817 and are sold as SILWET(copyright) surfactants by OSI Specialties Company, Greenwich, Conn. The preferred hydroxyl terminated polyether polysiloxane copolyols are SILWET(copyright) L-7200, L-7210, L-7230, L-7604, L-7608, L-7614 and L-7657 silicone glycol copolymers. Silwet Surfactants L-7200, L-7210 and L-7230 are alkyl pendant polyether-modified silicone copolymers, namely hydroxy terminated copolymers.
Table A compares solubility characteristics of seven benzoate esters of SILWET(copyright) L-7200, L-7210, L-7230, L-7604, L-7608, L-7614 and L-7657 silicone glycol copolymers.
The hydroxyl terminated polyether polysiloxane copolyols may also be obtained from Dow Corning (Midland, Michigan) as Dow Corning(copyright) 190 and 193 surfactants (Formula IV above).
The hydroxyl terminated polyether polysiloxane copolyols are also available from Goldschmidt Chemical Co., Inc. of Hopewel, Va., USA as ABIL(copyright) B 8842, 8843, 8847, ABIL(copyright) B 88183 and others (Formula III). ABIL(copyright) polyether siloxanes are block copolymers comprising a linear or branched-chain polysiloxane block and one or more polyether blocks.
In manufacturing the compounds of this invention, a benzoic acid is reacted with the hydroxyl terminated polyether polysiloxane copolyol.
Generally, the benzoic acid is reacted with the hydroxyl terminated polyether polysiloxane copolyol in stoichiometric amounts with a slight excess of the benzoic acid present. The starting materials are usually employed in stoichiometric proportions, but may be employed in amounts corresponding to from 1 to 1, and most preferably from 1 to 0.8, but can go as low as 1 to 0.5 with excellent results. The reaction may be carried out batchwise or in a continuous manner. A batch process is preferred.
A catalyst is present during the reaction. Among the catalysts which may be used are stannous oxalate, methane sulfonic acid, and the like.
The reaction is preferably conducted under an inert atmosphere of nitrogen at a reaction temperature of from 200xc2x0 C. to 300xc2x0 C., and preferably from 210xc2x0 to about 235xc2x0 C., and most preferably from 220xc2x0 C. to 230xc2x0 C. The acid value of the reaction is determined by procedures well known in the art. A reduced acid value indicates completion of esterification. When the acid value indicates that substantially all of the benzoic acid has been consumed, the reaction mass is then cooled to between about 100xc2x0 and 130xc2x0 C., and preferably from about 110xc2x0 to 120xc2x0 C., treated with Hydrogen Peroxide and then further cooled to about 25xc2x0 C. or greater. The reaction mass is then filtered using filter aids such as diatomaceous earth, cellulose, or a silicate type filter aid and the like. The products of the reaction are a clear colorless to light yellow liquids.
The preferred benzoate esters of the invention are Dimethicone PEG/PPG-20/23 Benzoate (referred to herein as FINSOLV(copyright) SLB-101) and Dimethicone PEG-8 Benzoate (referred to herein as FINSOLV(copyright) SLB-201).
In a specific embodiment, and by way of illustration, this invention contemplates the production of benzoate esters of hydroxyl terminated polyether polysiloxane copolyols in accordance with the following equation to produce FINSOLV(copyright) SLB-101: 
(Dimethicone Polyol (Cas #68937-55-3)+Benzoic Acidxe2x86x92Dimethicone Copolyo Benzoate (or Dimethicone PEG/PPG-20/23 Benzoate, i.e., FINSOLV(copyright) SLB-101)
(Dimethicone Polyol (Cas #68937-55-3) +Benzoic Acidxe2x86x92Dimethicone Copolyol Benzoate (or Dimethicone PEG/PPG-20/23 Benzoate, i.e., FINSOLV(copyright) SLB-101)
In a second specific embodiment, and by way of illustration, this invention contemplates the production of benzoate esters of hydroxyl terminated polyether polysiloxane copolyols in accordance with the following equation to produce FINSOLV(copyright) SLB-201: 
(Dimethicone Polyol (CAS #68937-54-2) +Benzoic Acid (CAS #65-85-0)xe2x86x92Dimethicone Copolyol Benzoate (or Dimethicone PEG-8-Benzoate, i.e., FINSOLV(copyright) SLB-201)
The preferred benzoate esters of the invention, FINSOLV(copyright) SLB-101 and FINSOLV(copyright) SLB-201, are based on a selected, but different, range of molecular weights of varying ratios of EO/PO (Ethylene Oxide/Propylene Oxide). The backbones of these two benzoate esters are EO/PO on a silicone glycol. They are highly hydrophilic and are designed to be used in aqueous systems where clarity and/or high degree of emollient solubility is desirable. Typical properties of the benzoate esters of the invention are described in Table B.
Table C below compares the solubility of the preferred benzoate esters of the invention in various solvents. The solubility is based on 1 gram of benzoate ester in 10 gm. solvent. Variations of properties and solubilities can be achieved by using different grades of SILWET(copyright) surfactants.
FINSOLV SLB-101 and FINSOLV SLB-201 are useful in all types of skin, hair and decorative products. Hand and face creams benefit from their unique feel on the skin and spreading properties. Bath and shower products as well as shampoos and conditioners, will have improved after-feel due to the specially selected silicone backbone. Color cosmetics will spread easier and have better wetting and leveling effects in the dispersion of pigments. Use of these esters at a very small level (0.1-0.5%) in bar soaps or syndet bar soaps imparts excellent skin feel without the soap feel. They also find use in skin care lotions, shaving soaps/foams, hair sprays and in perfumes/colognes.
FINSOLV(copyright) SLB-101 and FINSOLV(copyright) SLB-201 are also useful in the treatments of fibers, textiles and non-woven substrates such as tissues and wipes, lending a smooth, hydrophilic finish. Such substrates are used in skin cleansing applications.
The aforedescribed benzoate esters have the following properties:
1. Water solubility/dispersibility.
2. Ease of emulsification.
3. Emulsifier/co-emulsifier with other emollients.
4. Emolliency at body temperature with good after-feel.
5. Lack of greasiness, pleasant skin feel.
6. Lack of oiliness while imparting good lubrication.
7. Foam improvements.
8. Unusually low surface tension.
10. Bland odor.
11. Alcohol (ethanol) solubility.
12. Dispersibility in propylene glycol/glycerine/water.
13. Allows more water in some systems.
14. Low toxicity.
15. Acid, alkaline stability.
16. Solvents for many common skin and hair additives, including, sunscreens and over-the-counter therapy xe2x80x9cactivesxe2x80x9d.
Some of the benefits/advantages of the benzoates of hydroxyl terminated polyether polysiloxane copolyols of the invention are:
The benzoate esters of this invention are advantageous in that they are non-oily, tasteless, inert, essentially non-toxic and non-sensitizing, stable, and exhibit inverse solubility. They are hydrolytically stable and are soluble in water, alcohol and hydroalcoholic systems. For cosmetics and personal care products, they function in surface tension reduction, as wetting agents, and as emulsifiers/modifiers. For hair care products, they plasticize resins in hair spray, impart a silky feel to hair and aid in reduction of combing force, both wet and dry. In skin care products, they increase foam volume and the nature of the foam (bubble size, etc.), they improve wetting and lubricity of skin lotions, have lotions and creams/lathers.
The benzoate esters of this invention are useful as:
Emollients, solubilizers
Moisturizers, plasticizers
Sunscreen vehicles/solvents
Hair conditioners/detanglers
Wetting agents for powders (TiO2, ZnO, etc.)
De-oilers/degreasers
Emulsifiers/co-emulsifiers
Foam-modifiers
Facial cleansers
The foregoing list is only exemplary of the type of compositions in which the benzoate esters of this invention may be used and, as such, is not to be considered limiting.
The amount of benzoate ester used in an aqueous surfactant composition is dependent on the type of composition desired, the type and quantity of other ingredients used, e.g. cosmetic ingredients, and the amount and type of functional additives that are utilized. Typically, the amount of benzoate ester used ranges from about 0.5% to about 50% by weight of the aqueous surfactant composition. Preferably, from about 0.5% to about 5.0% of benzoate esters of this invention are used.
The aforementioned.benzoate esters have unique properties. In particular, they have foam modifying properties, which means that the benzoate esters of the invention confer any or all of the following properties upon a surfactant composition:
Flash foam increase;
Foam volume increase;
Foam viscosity increase or decrease;
Foam cell size increase or decrease.
While the particular foam modification is dependent upon the benzoate ester and surfactant of choice, none of the compounds suppress foam volume, i.e., none of the benzoate esters investigated are defoamers. Additionally, they have other properties which make them suitable for use as emollient carriers and for use as solvents.
The beenzoate esters of the invention are useful as foam modifiers for aqueous surfactant compositions such as hand cleaners, bath compositions, facial cleansers, cleansing creams, hard surface cleaners, shampoos, mousse products, shaving creams, pet cleaners, and concrete air-entrainment products.
Further, the benzoate esters of this invention possess other unusual physicochemical properties, in particular, low surface tension which can make them beneficial and unique components of sophisticated delivery systems such as in hand, face, and body creams and lotions.
The benzoate esters of this invention may be used in skin care compositions. The amount used in skin care compositions is dependent on the type of skin care compositions, the type and quantity of cosmetic ingredients used and the amount and type of functional additives. Typically the amount ranges from about 0.5% to about 80%, by weight, of the skin care compositions. For example, a facial cream may only have about 0.5%, where a massage oil may have up to about 80% by weight. Still higher amounts may be used in, for example, bath oils, e.g. 95%.
Further, the benzoate esters described herein may also function as plasticizers for polymers contained in skin care compositions, may be auxiliary suspending agents capable of assisting in the suspension of ingredients in skin care compositions and also may function as a dye leveling agent and dye carrier. Thus, the benzoate ester when used in skin care compositions serves not only as an emollient and carrier but also exhibits one or more other functions.
Table C is a Table of Identification which identifies products both known and produced by the process of this invention. For ease of identification each ester is identified by an internal Reference Number, and a Trade Name, where available. This identification system is used in the subsequent Tables and Examples.